Drill-steel centralizer



C. C.-HAN$EN DRILL STEEL CENTRALIZER Jan. 11 1927.

Filed July 27. 1926 IN VENT OR THUJ.

I H/J Ar ORNEY.

Patented Jan. 11, 1927.

nsrrsn stares PATENT orrics.

CHARLES C. HANSEN, OF EASTQN, PENNSYLVANIA, ASSIGNOR TO ENGERSOLL-RANDCOMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATIGN OF NEVT JERSEY.

DRILL-STEEL CENTRALIZER.

Application filed July 27,

This invention relates to rock drills ot the hammer type and especiallyto a device for the purpose of centralizing the drill steel. Theinvention provides features of novelty when applied to guiding andcentralizing the drill steels of channeling drills.

An object of this invention is to cause the drill steel to strikerepeated blows on the same spot during the process broaching or ofstarting the hole to be drilled, especially when the rock surface isinclined to the axis oi the drill steel.

further objects of this invention will hereinafter appear and can bemore clearly explained by reference to the accompanying drawings inwhich Figure 1 is a side view of the end of drill shell with thecentralizer mounted thereon and the drill steel in its proper positionwith respect to the drill shell and the drill centralizer,

Figure 2 is an enlarged cross sectional view of the centralizer,

Figure 3 is a longitudinal sectional view ot the centralizer showing thewearing blocks in position and showing the method of attaching thecentralizer to the drill shell,

Figure 4 is a longitudinal sectional view of the centralizer showing apair of wearing blocks removed to receive a drill steel of rectangularcross section, as for instance a channeling bar, and

Figure 5 is a perspective view of one of the removable wearing blocks.

Referring to the drawings a rock drill front head A is part of asuitable rock drill n'iounted on the shell B. A drill steel G extends inthe well-known manner into the trout head A to receive blows of impactdelivered by the hammer piston or anvil block, (not shown) depending onthe type of rock drill employed. The rock drill is slidably mounted uponthe shell B and may be moved forward or backward in order to keep thecutting end of the drill steel C in contact with the rock or to removethe tool from the hole. This longitudinal movement may be accomplishedby means of a feed screw (not shown). The function of the centralizer isto keep the bit E of the drill steel O on the desired point on the rockwhile permitting longitudinal motion of the drill steel C. Motion in anyother directien is prevented.

Centraiisere especially adapted to be 1926. Serial No. 125,239.

used in certain quarrying methods which require that a row of holes F(Fig. 1) be drille l to a certain depth and that the par titions' orwalls between these holes be broken out'by means ot a specially shapeddrill steel, known as a channeling or broaching bit.

in accordance with the above mentioned requirements the centralizerincludes a frame rigidly secured to the drill shell i? (Fig. 1) by boltsJ extending longitudit ot the shell. The frame H is spaced from the endoi the shell B by suitable 's'l PZXCGIS or washers J about the bolts J.Freterably the frame H is U shaped havng outwardly extending arms H oneither side of the drill steel C. Each arm H is tormei of twoprojections between which a bolt K is pivotally mounted, the threadedend of the bolt K being adapted to extend beyond the ends of the arm H.

In order to secure wearing blocks N firmly in place, a wearing block 0is provided closely fitting within the parallel arms of the primary yokeM and secured thereto by means of bolts P. In addition to securingwearing blocks N firmly in place, the wearing block or secondary yoke 0provides a suitably shaped recess for a drill steel of different crosssectional shape it the wearing blocks N are removed.

Between the arms H" the U shaped yoke M is adapted to be reinovablysecuredby the bolts K.

The drill steel C is adapted to be held slidably in place by means ofthe wearing blocks 0, N and Q. These blocks placed in the positionsdescribed form a cylindrical opening R to accommodate the round drillsteel C.

Figure 5 shows the shape of each of the wearing blocks N. This block hastwo parallel faces N. a concave face S to bear against the steel 0, anopposed plane face T and a head or flange to assist in holding theblocks N in position between the blocks 0 and Q.

In Figure 3 the wearing blocks N are shown in place. This assembly showsin dash-dot lines a round drill steel C occupying the cylindrical recessformed by the wearing blocks N, the secondary yoke or wearing block 0,and the wearin block Q.

in Fig. 4 the wearing blocks i and the round driil steel G are removedand lUD tzzngnlar drill steel G placed in the rectangular recess soformed,

The flanges V (Figs. 1: and 5) are for convenience in assembling and toinsure accurate placing of the blocks N and Q and the secondary yoke 0.

Special advantages of this invention are the convenience of assembly andthe rapidity with which the round drill steel may be replaced by one ofrectangular cross section. To accomplish this change the drill steel isfirst withilrmvn from the hole F in the rock by means of thelongitudinal. teed screw, the bolts K are loosened and swung sideways topermit removal of yoke M and the blocks N and the rectangular broachingsteel G in placed in the centralizer leaving out the blocks N andrelastening the yoke M in place by means of the bolts K.

I claim:

A drill steel contralizer comprising a frame, a pair o l pivotallymounted loohts a yoke clamped rigidly to said frame by means of saidbolts and having two parallel arms, and removable Wearing blocks ir saidyoke, said yoke holding Said Wearing blocks firmly in place, a pair ofsaid wearing blocks adapted to be removed to ILCQQ UHLEOLlH IG drillsteels of ditl'ercnt cross sectional shape.

In testimony whereof I have signed this specification.

CHARLES C. HANSEN.

